Cylindrical Screen Research Articles

Numerical simulation and optimization of heat pipes using nanoparticles: a feasibility study

This study investigated the effect of different particle sizes on the thermal effectiveness of a cylindrical screen mesh heat pipe using silver nanoparticles as the test substance. The study compared the effects of three different particle sizes (30, 50, and 80 nm) on heat transmission characteristics of the heat pipe. The results showed that the heat pipe’s thermal conductivity increases as the particle size decreases. The thermal conductivity measurements revealed 250 W/mK, 200 W/mK, and 150 W/mK for particles of 30, 50, and 80 nm sizes. Furthermore, the study analyzed thermal resistance of heat pipe for each particle size and found that as particle size decreases, thermal resistance decreases as well. The heat transfer coefficient values for particle sizes of 30, 50, and 80 nm were found to be 5500 W/m2K, 4500 W/m2K, and 3500 W/m2K, respectively. The ANOVA method was used to analyze the results statistically. The 30 nm particle size was found to have significantly higher thermal conductivity, lower thermal resistance, and a higher heat transfer coefficient than other particle sizes. Additionally, simulations were conducted to analyze the temperature variation of the hot source as a function of power dissipation for design and optimization.

Predicting the thermal performance of screen mesh wick heat pipe with alumina nanofluids using response surface methodology

This study aims to investigate the effect of heat load, tilt angle, and volume concentration of alumina nanofluid on the thermal performance enhancement of cylindrical screen mesh wick heat pipe in terms of thermal resistance(R) and thermal conductivity(k). Response surface methodology based on the Box–Behnken design was implemented to investigate the influence of heat input (100–200 W), tilt angle (0–90°), and volume concentration (0.05–0.25 vol%) of nanofluid as the independent variables. Second-order polynomial equations were established to predict the responses, ‘R’, and ‘k’. The significance of the models was tested by means of analysis of variance (ANOVA). In addition, a correlation between the independent variables was derived in this study. The results revealed that the optimum heat input, inclination angle, and concentration of nanofluid were determined as 200 W, 52.72°, and 0.1773 vol. % respectively for both ‘R’ and ‘k’. SEM analysis was performed to observe the thermal performance phenomena of the heat pipe before and after experimentation.

Nanoparticle Size and Heat Pipe Angle Impact on the Thermal Effectiveness of a Cylindrical Screen Mesh Heat Pipe

This study examines the effects of particle size and heat pipe angle on the thermal effectiveness of a cylindrical screen mesh heat pipe using silver nanoparticles (Ag) as the test substance. The experiment investigates three different particle sizes (30 nm, 50 nm, and 80 nm) and four different heat pipe angles (0°, 45°, 60°, and 90°) on the heat transmission characteristics of the heat pipe. The results show that the thermal conductivity of the heat pipe increased with an increase in heat pipe angle for all particle sizes, with the highest thermal conductivity attained at a 90° heat pipe angle. Furthermore, the thermal resistance of the heat pipe decreased as the particle size decreased for all heat pipe angles. The thermal conductivity measurements of the particle sizes—30, 50, and 80 nm—were 250 W/mK, 200 W/mK, and 150 W/mK, respectively. The heat transfer coefficient values for particle sizes 30 nm, 50 nm, and 80 nm were 5500 W/m2K, 4500 W/m2K, and 3500 W/m2K, respectively. The heat transfer coefficient increased with increased heat pipe angle for all particle sizes, with the highest heat transfer coefficient obtained at a 90° heat pipe angle. The addition of Ag nanoparticles at a volume concentration of 1% reduced the thermal resistance of the heat pipe, resulting in improved heat transfer performance. At a heat load of 150 W, the thermal resistance decreased from 0.016 °C/W without nanoparticles to 0.012 °C/W with 30 nm nanoparticles, 0.013 °C/W with 50 nm nanoparticles, and 0.014 °C/W with 80 nm nanoparticles. This study also found that the heat transfer coefficient increased with increased heat pipe angle for all particle sizes, with the highest heat transfer coefficient obtained at a 90° heat pipe angle.

Study on Migration Law of Solid Particles on Sieve Surface of Solid-liquid Separator

Based on the discrete element method and the three-dimensional discrete element analysis software EDEM, simplify the tube net type solid liquid separator model, to explore the net type solid liquid separator inside the cylindrical screen opaque screen the migration law of solid phase particles and different vibration frequency, vibration amplitude, vibration direction Angle, diameter of sieve sieve speed and sieve cylinder is opaque screen the influence of solid phase particles migration rule, In order to provide reference for the selection of structural parameters and vibration parameters of solid-liquid separator in field application. The results show that the motion trajectory of solid particles on the screen is a three-dimensional spiral curve. The larger the vibration frequency and amplitude of the screen box, the higher the particle migration speed. The larger the vibration direction Angle, diameter and speed of sieve box, the smaller the particle migration speed. The research results can be used for reference in the selection of structural parameters and motor vibration parameters that affect the comprehensive performance of the cylinder net solid-liquid separator.

Influence of Cylindrical Shield Dimensions on Shielding Effectiveness

Study of dimensional parametersʼ influence on shielding properties of cylindrical shields will allow to optimise the fusion process, as well as to reduce production costs by reducing the material used. The purpose of this work was to compare results of theoretical calculation of shielding effectiveness of an infinite cylindrical shield with the data obtained in real conditions.A cylindrical Ni-Fe shield was synthesised by electrochemical deposition with length of 32 cm, diameter of 4.5 cm and shielding thickness of ≈ 100 µm. The cylinder length was then reduced from 32 cm to 6 cm in 4 cm increments and for each cylinder length shielding effectiveness was measured using three-coordinate Helmholtz field-forming system.The measurement results show that the calculation of shielding effectiveness of infinite cylindrical shield is valid for cylinder lengths l ≥ 18–20 cm. Shielding effectiveness is markedly reduced at values of l ˂ 15 cm.Analysis of data obtained allowed to conclude that it is necessary to determine the correction factor when calculating a cylindrical screen shielding efficiency

Research Paper on Screen Printing Machine for Cylindrical Shape

Abstract: Screen printing is a technique of applying a pressure of certain quantity of colouring agent into a specified surface to form a text and lot of development is taken place. Screen printing has application in Wedding cards, Stickers printing, T-shirts, Business cards and textile industries. We have introduced a screen printing machine for cylindrical shape. Cylindrical Screen Printing equipment prints cylindrical objects with a flat printing screen. It works for printed objects like bottles, buckets, drums, etc. Cylindrical printing press can put a more thick, clear color than label printing. At the same time, with its direct color putting, an automatic cylinder printing equipment may finish the all printing process only needing you to put the object on the enter. Keywords: Screen Printing , cylindrical shape

Study of the Fluid Passing through the Screen in the Three Products Hydrocyclone Screen (TPHS): A Theoretical Analysis and Numerical Simulation

The three products hydrocyclone screen (TPHS), a branch of the hydrocyclone, effectively removes the fish-hook effect, which has been used in the industrial field. The current cylindrical screen in the TPHS generates the characteristic flow known as the screen underflow, which has a significant impact on device performance. To investigate the flow behaviour of the fluid passing through the screen, a combination of a dynamic analysis and a numerical simulation was used. The permeating process in the TPHS was abstracted by a simple fan mode in this work to generate the flow-rate equations and the driving-force models. The pressure difference was the driving force for the screen penetration in the ideal fluid, but it also included a viscous force in the viscous fluid. Furthermore, at the same inlet velocity, the viscous fluid had a higher flow rate than the ideal, indicating that the viscosity promoted the fluid penetration. Meanwhile, as the inlet velocity increased, the mass flow of the screen backflow increased, while the corresponding proportion first rose to a peak then dropped and then gradually stabilised. Furthermore, a flow equation for the screen underflow in the TPHS was developed, which is related to the structural parameters (the rotation radius, the length of the cylindrical screen, the aperture size, and the open-area percentage) and the process parameters (the dynamic viscosity of the fluid and the pressure difference between the feed inlet and the screen outlet).

The Application of the Combination of Virtual and Reality in the Film Space Performance

In order to improve the effect of film space performance, this paper applies the combination of virtual and reality to the film space performance processing. Moreover, this paper analyzes the light field distribution of the three-dimensional object in space, and modulates the projected image projected on it with the spectral characteristics of the optical screen to finally restore the light field of the original object. In addition, this paper uses the multi-projection method to study the recovery process of the cylindrical microlens array screen to the light field, and divides and reorganizes the multi-view image of the scene shot by the camera array to obtain the correct projected image. Finally, this paper applies the space processing algorithm based on the combination of virtual and reality to the film space performance processing, and uses experimental research to verify the reliability of the method proposed in this paper.

Cooled ferromagnetic shield as a part hybrid system for isolation of a flux qubit from electromagnetic environment

Currently, circuits for quantum informatics, communications and measuring equipment containing superconducting flux qubits in a planar design are being created by quantum engineering techniques. To function, such structures must be cooled in a refrigerator down to about 10 mK. The flux qubits have linear size of superconducting circuit of some tens of micrometers and are very sensitive to external magnetic fields and their variations. The qubit built in the gradiometer-like design has reduced sensitivity to external uniform magnetic fields, but remains quite sensitive to their variations. To protect the qubit from unwanted external magnetic fields, which include the Earth's field, man-made fields, and residual magnetic fields of the cryostat parts, it is necessary to create efficient magnetic shields. Earlier, we proposed a scheme for a single-photon microwave counter, in which a planar flux qubit in a gradiometer version serves as the receiving element. To let it function properly, a 3-layer hybrid magnetic shield composed of two superconducting and one ferromagnetic cylinders, has been designed for installation in a dilution refrigerator at 10 mK temperature. The effectiveness of such a shield depends on the correct design of all three shells. This paper presents the results of calculation and magnetic measurements of a cylindrical ferromagnetic screen made of low-temperature permalloy Cryoperm 10 in dc and low-frequency alternating magnetic fields. Cryoperm 10 keeps high magnetic permeability at liquid helium temperatures and below. It is shown that this shield is able of reducing the absolute value of the magnetic field and its variations by 55-70 dB. Together with superconducting lead magnetic shields, this design will reduce the absolute value of the field by 70 dB, and the field variation by 200 dB, which will provide the necessary conditions for the operation of a single-photon counter based on a flux qubit.

Analytical solution of problem of shielding low-frequency magnetic field by thin-walled cylindrical screen in presence of cylinder

The analytical solution of boundary value problem describing the process of penetration of low-frequency magnetic field through thin-walled cylindrical screen with cylindrical inclusion is constructed by use of approximate boundary conditions. The source of the field is a thin thread of infinitely small length with an infinitely small cross-section where current circulates. Thread is located in a plane which is perpendicular to axis of cylindrical screen, in outer region with respect to a screen. Initially the potential of initial magnetic field is represented as spherical harmonic functions, then using addition theorems connecting spherical and cylindrical harmonic functions, it became as cylindrical harmonic functions superposition. Secondary potentials of magnetic field are also presented as superposition of cylindrical harmonic functions in three-dimensional space. It is shown that the solution of formulated boundary value problem is reduced to the solution of linear algebraic equations system for coefficients included in the representation of secondary fields. The influence of some aspects of the problem on the value of the screening coefficient of an external magnetic field when passing through a cylindrical copper screen in the presence of a cylindrical inclusion is studied numerically. Calculation results are presented in graphs form. Obtained results can be used to shield technical devices and biological objects against the effects of magnetic fields to provide ecological surrounding of operating electrical installations and devices.

Reduction in the Electromagnetic Interference Generated by AC Overhead Power Lines on Buried Metallic Pipelines with Screening Conductors

This paper presents a numerical study on the reduction in the voltage and current induced on a 13.5 km buried metallic pipeline by an overhead power line. The mitigation effectiveness of different configurations and cross-section shapes of screening conductors is computed by means of a methodology that combines a 2D Finite Element Analysis with circuital analysis. A 35.72% reduction of the maximum induced voltage is obtained when 4 cylindrical steel screening conductors with 8 mm radius are buried 0.25m below the soil surface, along the pipeline path. The maximum induced pipeline current is reduced by 26.98%. A parametric study is also performed, to assess the influence of the per-unit-length admittance to earth of the screening conductors on the mitigation efficacy. The results show that screening conductors may help in reducing the inductive coupling between overhead power lines and buried metallic pipelines, and that the assumption of perfectly insulated screening conductors leads to an underestimation of the produced mitigation effect.

Process Parameter Screening for the Microalga Chlamydomonas asymmetrica in Batch and Turbidostat Cultivations

AbstractAlgae offer tremendous potential for the production of various high‐value products (HVPs). Besides the light quantity and quality, factors such as temperature, medium composition, pH, and aeration are important algae‐specific process parameters that influence growth behavior and their chemical composition. Screenings for algae and their HVPs are ongoing, but the available data for their cultivability and suitability as production organisms are limited. Turbidostat processes enable a simple and fast screening for light‐specific influences, as constant biomass concentrations will result in constant self‐shading. Here, the microalgae Chlamydomonas asymmetrica was cultivated in cylindrical photobioreactor screening modules. A detailed characterization the light and temperature dependency of the organisms' HVPs is provided.

Computational Modeling of Flow Characteristics in Three Products Hydrocyclone Screen

Three products hydrocyclone screen (TPHS) can be considered as the combination of a conventional hydrocyclone and a cylindrical screen. In this device, particles are separated based on size under the centrifugal classification coupling screening effect. The objective of this work is to explore the characteristics of fluid flow in TPHS using the computational fluid dynamics (CFD) simulation. The 2 million grid scheme, volume fraction model, and linear pressure–strain Reynolds stress model were utilized to generate the economical grid-independence solution. The pressure profile reveals that the distribution of static pressure was axisymmetric, and its value was reduced with the increasing axial depth. The maximum and minimum were located near the tangential inflection point of the feed inlet and the outlets, respectively. However, local asymmetry was created by the left tangential inlet and the right screen underflow outlet. Furthermore, at the same axial height, the static pressure gradually decreased along the wall to the center. Near the cylindrical screen, the pressure difference between the inside and the outside cylindrical screen dropped from positive to negative as the axial depth increased from −35 to −185 mm. Besides, TPHS shows similar distributions of turbulence intensity I, turbulence kinetic energy k, and turbulence dissipation rate ε; i.e., the values fell with the decrease in axial height. Meanwhile, from high to low, the pressure values are distributed in the feed chamber, the cylindrical screen, and conical vessel; the value inside the screen was higher than the outer value.

50‐1: Omni‐Directional Projection VR Systems Using Ultra‐Short Throw Lenses

We have developed a novel ultra‐short throw lens with catadioptric relay which can project a large image on curved screens with remarkably uniform brightness and pixel size distribution. This wide projection enables a compact omni‐directional projection VR system with only eight projectors as well as a cylindrical screen VR system.

Development of a vibrationless sorting system

Aim of study: Size classification is essential in many industrial processes. Most classical sorting systems use vibrations as a means of classification function. In this study, a vibration-free sorting system called helical cylindrical screen has been developed against the disadvantages of vibrating systems and proposed to be used in the sorting of crop seeds.Area of study: Adana City, Turkey.Material and methods: The movement of the seed mass on the screen surface was formulated and the mass movement along the circular-helical paths was analytically expressed, leading to some operational parameters for evaluation in the screen design. By combining the mass movement parameters with effective separation conditions, an algorithm was obtained against the desired mass flow rate to determine the appropriate values of the design parameters. Experiments were performed on the machine, which was manufactured to sort peanut seeds into two different sizes, small and large.Main results: The results obtained in the experiments (separation efficiency, mass flow rate, effect of grain size on separation efficiency and equilibrium angle) were compared with the theoretical ones. The separation efficiency of the machine (99% and above) was quite good and is not affected at all by the small size ratio contained in the mixtures. The limitations of the theoretical velocities (axis and tangent) of a seed moving on the cylindrical sieve were found to be consistent with those obtained experimentally.Research highlights: The helical cylindrical sieve can be used for other particulate agricultural products with smooth surfaces such as soybeans, kidney beans, peas, etc.

Mechanism of the Absent Air Column in Three Products Hydrocyclone Screen (TPHS): Experiment and Simulation

Three products hyrdrocyclone screen (TPHS) has been proposed for particle separation based on size. In TPHS, a cylindrical screen was embedded in a conventional hydrocyclone (CH) to combine the centrifugal classification and screening to particle separation based on size. The industrial application of TPHS indicates its better device performance than CH. Although, the earlier studies reveal some common understanding for TPHS, the information of the absent air column remains unknown. Hence, the combination of physical experiment and numerical simulation was considered involving a 75 mm TPHS for this knowledge gap. First, both the computational fluid dynamics (CFD) simulation with Reynolds stress mode and the physical experiment with a high-definition camera illustrate the development process details of a flow field in TPHS. That is, the water was imported along the tangential inlet into TPHS; then under the effects of the feed chamber wall and gravity, the liquid phase spiraled downward until the cylindrical screen passed through the sieve; as the liquid moved to the spigot, it could be discharged in time due to the small underflow port, thus the volume fraction of air rapidly reduced from 1 to 0; subsequently the water filled the TPHS and the absent air column could be observed. Furthermore, the distribution comparisons of air volume fraction and static pressure show that TPHS displayed the absent air core with the negative static pressure in the center region along the z-axis, while CH displayed the opposite features. In addition, despite the different inlet velocity, TPHS consistently presented the vanished air column which could be ascribed to the fact that the present cylindrical screen resulted in positive static pressure distribution inside TPHS.

Research on the features of particles passing through screen in the three products hydrocyclone screen (TPHS)

This paper aims to investigate the features of particles passing through screen in a new Three Product Hydrocyclone Screen (TPHS). The result shows that with the increasing feed concentration, particles reporting to overflow, underflow and screen underflow become coarser, finer and bigger, respectively; as the feed pressure increases, those first increases then decreases, rises and falls, respectively; with the increase of spigot size, those become coarser, bigger and stable, respectively. Further, the optimum feed concentration, feed pressure and spigot size were 120 g/l, 0.07 MPa and 17.50 mm, respectively. Moreover, as the feed concentration, feed pressure or spigot diameter increases, both the average particle size and concentration of fluid permeating screen raises, while the permeating throughput decreases as either the increasing feed concentration or the decreasing feed pressure and spigot diameter. Besides, the deeper axial depth of cylindrical screen, the less particles penetrating screen.

Research on the features of particles passing through screen in the three products hydrocyclone screen (TPHS)

This paper aims to investigate the features of particles passing through screen in a new Three Product Hydrocyclone Screen (TPHS). The result shows that with the increasing feed concentration, particles reporting to overflow, underflow and screen underflow become coarser, finer and bigger, respectively; as the feed pressure increases, those first increases then decreases, rises and falls, respectively; with the increase of spigot size, those become coarser, bigger and stable, respectively. Further, the optimum feed concentration, feed pressure and spigot size were 120 g/l, 0.07 MPa and 17.50 mm, respectively. Moreover, as the feed concentration, feed pressure or spigot diameter increases, both the average particle size and concentration of fluid permeating screen raises, while the permeating throughput decreases as either the increasing feed concentration or the decreasing feed pressure and spigot diameter. Besides, the deeper axial depth of cylindrical screen, the less particles penetrating screen.

Why cylindrical screens in the Columbia River (USA) entrain few fish

Cooling-water intakes often entrain large numbers of larval and juvenile fish, leading to questions why a water intake on the Columbia River, USA, with axial flow, cylindrical screens on a T-screen structure entrained very few (four fish in 4,007 x 103 m3 of water sampled over four years). This is despite being downstream of spawning areas for Chinook salmon Oncorhynchus tshawytscha releasing up to 56 million pre-smolts and having screens consisting of porous plate with 9.5-mm-diameter pores capable of passing salmon fry and other small fish (poor physical exclusion). Multiple publications of experiments and observations in hydraulics and biology are used to help explain the low entrainment, concluding that effects of the screening structure rather than the actual screen are most important. Primary mechanisms appear to be: (1) bow-wave-like hydraulics at the structure’s nose cone that deflect small fish away from the screen’s pores, and (2) fish detection and avoidance of pressure and velocity changes upstream of the structure that aid deflection. These combined hydraulic and biological-behavior effects of the structure would cause salmon fry and other small fish to bypass the screened portion of the intake. At the screens, (3) high ratio of sweeping flow to approach and through-screen velocities likely further prevents entrainment. Although site- and design-dependent, this analysis may be useful for evaluating or planning other screen installations and focusing regulatory attention on hydraulics of the structure as well as the screen.

ПОВЫШЕНИЕ ЭФФЕКТИВНОСТИ ПРОЦЕССА КЛАССИФИКАЦИИ МАТЕРИАЛА В КЛАССИФИЦИРУЮЩЕЙ ПЕРЕГОРОДКЕ ШАРОВОЙ МЕЛЬНИЦЫ

Ball mills are widely used for dispersion of materials in various industries, as they are characterized by ease of maintenance, operation and sufficiently high performance. To improve the process of inner-chamber classification of coarse-ground material, a new construction of the classifying partition with blades having cylindrical screening surfaces is proposed. The aim of the research is to substantiate the effectiveness of the application of the developed construction of the classifying partition in an industrial ball mill. The tasks of the research are to study the effectiveness of the developed construction of the classifying partitions on industrial ball mill. The tasks are solved of constructing and analyzing a regression equation that adequately describes the efficiency of the process of classifying coarse material with a cylindrical sieving surface depending on variable factors, determining rational areas of their values; comparing the efficiency of using blades with cylindrical and flat screening surfaces for inner-chamber classification of coarse material; confirmation of the possibility of providing the developed classifying partition with the mass productivity necessary for the operation of the mill. In the course of the work, the methods of simulation and mathematical modeling were used. As a result of the study, the efficiency of using a classifying partition with blades with cylindrical screening surfaces of a ball mill D×L=2×10,5 is substantiated.